MEASUREMENT OF TEMPERATURE 33 



15. Which of the two thermometers should be 

 adopted for general use? Why? 



16. How is a thermometer made? 



17. How are the essential points of freezing and 

 boiling determined? 



18. What is the freezing point of mercury? Of 

 alcohol ? 



19. Why is a heat unit necessary ? 



20. What is the name of the heat unit used ? 



21. How much heat does this unit represent .' 



22. One gram of water has its temperature raised 

 20 C. How many calories of heat were used? 



23. The temperature of fifty grams of water was 

 raised 1 C. How many calories of heat were used ? 



24. How many calories of heat are required to raise 

 the temperature of 15 grams of water from 10 C. to 18 

 C.? From 32 F. to 50 F.f 



